Is it possible to have a lens recoated??

dwcdv wrote:

Hi Mitch,

I just came across your post where you say, only the Military can afford the recoating. I am looking for this company. I know, they are in Canada. Do you know their name?

The name I was referring is Zeiss (special products division),

You can even get Diamond-like coatings as the top layer so you can drop the lens in mud, and wipe it off with a dirty T-shirt and not harm the coating. When done in large batches, the cost is only prohibitive, when one one at a time.....not so.

NASCAR engines have the <titanium> valve stem coated with diamond-like coatings, and the <titanium> valve face coated with amorphous diamond. The coatings triple the cost of the valve compared to a top end valve--like Manley. These are done in batches of several thousand. With a vacuum chamber big enough for several hundred valves being coated at a time.

Hi Mitch,

The way you described how makers coat lens sounds like coating is very expensive, done in vacuum with tolerances in the submicron level. How can Walmart's sunglasses with anti-reflective coatings go as low as $15 a pair? What gives?

Artgrapher

Artgrapher wrote:

Hi Mitch,

The way you described how makers coat lens sounds like coating is very expensive, done in vacuum with tolerances in the submicron level. How can Walmart's sunglasses with anti-reflective coatings go as low as $15 a pair? What gives?

Artgrapher

Sales volume, automated manufacturing, and simplicity. They're just not made to anything like the same standards.  A one-off lens re-coating is uneconomical for the same reasons it's generally not worth repairing a $200 camera or lens.

Artgrapher wrote:

Hi Mitch,

The way you described how makers coat lens sounds like coating is very expensive, done in vacuum with tolerances in the submicron level. How can Walmart's sunglasses with anti-reflective coatings go as low as $15 a pair? What gives?

Artgrapher

My prescription eye glasses are no better than 2-3 waves of surface error, but since they are only correcting an image (rather than focusing an image) my eye can only tell when I use "optical stuff" to perform the lens analysis. So, where in the image formation process a lens is has a lot to do with how precise its surfaces have to be. Correctors do not have to be as good as focusers.

Secondarily, Walmart sunglasses are make in the millions (maybe millions per month) and at this kind of production rate, a batch of said lenses would consist of a sheet of transparent plastic maybe 20 feet by 8 feet in size that is run through a continuous vacuum chamber, and after coating the lenses are cut and formed (more like cookies before baking than optical parts). Given a high enough manufacturing rate and continuing demand, one can drive cost out of the manufacturing process. So, cheap plastics, coated in tennis court sized batched in a continuous process, and manufacture optimized to remove every cent of excess cost.